With an intent of helping parents control the spending of teens, pop superstar Justin Bieber has agreed to help promote a prepaid debit card offered by website BillMyParents.com.

With better than 30 million Twitter followers and 48 million fans on Facebook, Bieber’s involvement could bring significant activity to the prepaid card industry, which is not as strongly regulated as credit cards and the latest focus by banks seeking new revenues.

The SpendSmart card Bieber is to promote will be featured on a number of videos the singer will produce, underscoring the need for responsible spending by teenagers, according to the folks at LowCards.com.

Some wonder if it’s a dicey play considering prepaid cards don’t carry the same regulatory oversight as credit cards and regular debit cards. That could change, though, as the federal Consumer Financial Protection Bureau is just now gathering info on prepaid card practices and accepting input on ways to ensure users are protected.

And it’s not as if prepaid cards are a cottage industry. In 2011, consumers put more than $57 billion onto prepaid cards, according to the Mercator Advisory Group. Estimates are that loads will top $167 billion by 2014. Others who have backed prepaid card use include Magic Johnson, Suze Orman and a few cartoon characters.

Financial institutions love the revenue stream, which is not unlike ATM cards with $1.50-per-transaction fees on withdrawals, balance inquiry charges — even a fee for putting money onto the card in the first place. So much so that American Express and Chase have jumped in offering their own version of a card.

While a useful tool for parents to keep track of their kids’ spending — even a tool to teach them how to budget responsibly — some experts warn things could quickly get out of hand, with banks raking huge returns on fees.

A lot will depend on what the CFPB does with the industry and that isn’t likely to be known for several months.